Substrate for liquid crystal display panel, liquid crystal display panel, process of manufacturing substrate for liquid crystal display panel, and substrate testing method

Abstract

A liquid crystal display panel ( 1 ) includes: touch switches ( 50 ) each constituted by a switch electrode ( 52 ) of an active substrate ( 12 ) and a set of switch PS electrodes ( 51 ) of a counter substrate ( 11 ) so as to make conduct electricity when the active substrate ( 12 ) or the counter substrate ( 11 ) is pressed; and reflection coatings ( 38 and 39 ) which reflect infrared light emitted from a Fourier transform infrared spectrophotometer, the reflection coatings ( 38 and 39 ) being provided either in the active substrate ( 12 ) or the counter substrate ( 11 ) with the switch electrode ( 52 ) or the set of switch PS electrodes ( 51 ) stacked on a corresponding one of the reflection coatings ( 38 and 39 ). This provides a technique for efficiently determining the presence or absence of an alignment film on any touch switch provided inside of a liquid crystal display panel having the function of an in-cell touch sensor.

1 . A liquid crystal display panel substrate that constitutes a liquid crystal display panel by being placed opposite the other substrate with a liquid crystal layer sandwiched between the liquid crystal display panel substrate and the other substrate, the other substrate including a plurality of electrodes or plural sets of electrodes, the liquid crystal display panel substrate comprising:
 a plurality of switching electrodes or plural sets of switching electrodes each of which forms a switch with a corresponding one of the plurality of electrodes or with a corresponding one of the plural sets of electrodes, the plurality of switching electrodes or the plural sets of switching electrodes being each disposed so as to make electrical conduction with the corresponding one of the plurality of electrodes or with the corresponding one of the plural sets of electrodes when either the liquid crystal display panel substrate or the other substrate is pressed against the other with the liquid crystal display panel substrate placed opposite the other substrate; and   reflection coatings which reflect infrared light, the reflection coatings being disposed below each separate one of the plurality of switching electrodes or below each separate one of the plural sets of switching electrodes.   
     
     
         2 . The liquid crystal display panel substrate as set forth in  claim 1 , further comprising an alignment film formed so that surfaces of the switching electrodes serve as alignment-film-free regions on which the alignment film is selectively not provided, wherein
 when the liquid crystal display panel substrate is seen in plan view, each of the reflection coatings appears to be overlapping a corresponding one(s) of the alignment-film-free regions.   
     
     
         3 . The liquid crystal display panel substrate as set forth in  claim 1 , wherein the reflection coatings are made of a metal material. 
     
     
         4 . The liquid crystal display panel substrate as set forth in  claim 3 , wherein the metal material of which the reflection coatings are made is identical to a material of which wires or electrodes of an active substrate serving as the liquid crystal display panel substrate are made. 
     
     
         5 . The liquid crystal display panel substrate as set forth in  claim 3 , wherein the reflection coatings are composed mainly of tantalum, molybdenum, titanium, copper, or aluminum. 
     
     
         6 . The liquid crystal display panel substrate as set forth in  claim 1 , wherein each of the switching electrodes includes a transparent electrode. 
     
     
         7 . The liquid crystal display panel substrate as set forth in  claim 6 , further comprising pixel electrodes formed in a step identical to a step executed in forming the transparent electrode. 
     
     
         8 . The liquid crystal display panel substrate as set forth in  claim 6 , further comprising a common electrode formed in a step identical to a step executed in forming the transparent electrode. 
     
     
         9 . The liquid crystal display panel substrate as set forth in  claim 6 , wherein each of the switching electrodes is constituted by (i) the transparent electrode and (ii) a structure having a protruding shape with the transparent electrode stacked on the structure. 
     
     
         10 . The liquid crystal display panel substrate as set forth in  claim 9 , wherein the structure is made of acrylic. 
     
     
         11 . A liquid crystal display panel comprising:
 a liquid crystal display panel substrate as set forth in  claim 7 ; and   the other substrate placed opposite the liquid crystal display panel substrate.   
     
     
         12 . A liquid crystal display panel including an active substrate, a liquid crystal layer, and a counter substrate placed opposite the active substrate with the liquid crystal layer sandwiched therebetween, the liquid crystal display panel comprising:
 switches each constituted by a first switching electrode or a set of first switching electrodes of the active substrate and a second switching electrode or a set of second switching electrodes of the counter substrate so as to conduct electricity when the active substrate or the counter substrate is pressed; and   at least either first reflection coatings which reflect infrared light or second reflection coatings which reflect infrared light, the first reflection coatings being provided in the active substrate with the first switching electrode or the set of first switching electrodes stacked on a corresponding one of the first reflection coatings, the second reflection coatings being provided in the counter substrate with the second switching electrode or the set of second switching electrodes stacked on a corresponding one of the second reflection coatings.   
     
     
         13 . The liquid crystal display panel as set forth in  claim 12 , said liquid crystal panel includes both the first reflection coatings and the second reflection coatings. 
     
     
         14 . The liquid crystal display panel as set forth in  claim 12 , at least either (i) the first switching electrode or the set of the first switching electrodes or (ii) the second switching electrode or the set of second switching electrodes has(have) a protruding shape(s). 
     
     
         15 . The liquid crystal display panel as set forth in  claim 14 , the first switching electrode or the set of first switching electrodes and the second switching electrode or the set of second switching electrodes have protruding shapes. 
     
     
         16 . A method for fabricating a liquid crystal display panel substrate that constitutes a liquid crystal display panel being placed opposite the other substrate with a liquid crystal layer sandwiched between the liquid crystal display panel substrate and the other substrate, the other substrate including a plurality of electrodes or plural sets of electrodes, the method comprising:
 a reflection coating forming step of forming reflection coatings which reflect infrared light;   a switching electrode forming step of forming, above each separate one of the reflection coatings formed in the reflection coating forming step, a plurality of switching electrodes or plural sets of switching electrodes each of which forms a switch with a corresponding one of the plurality of electrodes or with a corresponding one of the plural sets of electrodes, and each of which makes electrical conduction with the corresponding one of the plurality of electrodes or with the corresponding one of the plural sets of electrodes when either the liquid crystal display panel substrate or the other substrate is pressed against the other with the liquid crystal display panel substrate placed opposite the other substrate.   
     
     
         17 . The method as set forth in  claim 16 , further comprising an alignment film forming step of forming an alignment film in an area around alignment-film-free regions on which the alignment film is selectively not deposited, the alignment-film-free regions being surfaces of the switching electrodes formed in the switching electrode forming step. 
     
     
         18 . The method as set forth in  claim 17 , further comprising:
 an infrared light emitting step of emitting infrared light onto the alignment-film-free regions;   a reflected light obtaining step of obtaining reflected light from the reflection coatings reflecting the infrared light emitted in the infrared light emitting step; and   a spectrum displaying step of displaying a spectrum of the reflected light obtained in the reflected light obtaining step.   
     
     
         19 . The method as set forth in  claim 18 , further comprising a determining step of determining, from the spectrum of the reflected light obtained in the reflected light obtaining step, whether the alignment film is present or absent. 
     
     
         20 - 25 . (canceled)